By-pass thermostat



B. R. HOMFELDT ET AL BY-PASS THERMOSTAT Feb. 21, 1956 Filed March 31, 1952 55 1NVENToR5,

United States Patent O BY-PASS THERMGSTAT Bransford R. Homfeldt and Qrlando J. Chiappe, Elgin, Ill., assignors to Flexonics Corporation, tiaywocd, lil., a corporation of illinois Application March 31, 1952, Serial No. 279,646

8 Claims. (Cl. 236-345) The invention relates to thermostats, and concerns particularly -by-pass thermostats for use in internal combustion engines and the like.

Automotive thermostats are generally of two types, viz., uniflow thermostats adapted to open or close, or partially close, the ow of the cooling liquid for the engine within a single passage in which the thermostat is mounted; and by-pass thermostats adapted to control and proportion the coolant ow between two passageways leading, respectively, to the radiator or in by-pass relation therewith.

By-pass thermostats, because of their nature and requirements, are frequently complex and cumbersome; becoming unduly ditcult to fabricate and assemble, and as a result unduly costly to produce.

It is an object of the present invention to provide a thermostat for internal combustion engines, specifically of the by-pass type, which is of improved construction and which has improved operating characteristics in service.

More specifically stated, it is an object of the invention to provide an automotive thermostat, of the by-pass type, which may be more readily fabricated and assembled, and which is of simplified construction, whereby to provide a thermostat structure of lower cost.

A further object of the invention is to provide an automotive thermostat of the foregoing type which, although of simplified construction, has satisfactory and improved operating characteristics, and is durable in service.

Still further objects of the invention are to provide an internal combustion engine by-pass thermostat, for controlling the coolant ow therein, having an improved proportioning valve arrangement, and an improved cooperative mounting with the associated flow passages of the engine block.

Various other objects, advantages and features of the invention will be apparent from the following specification, when taken in connection with the accompanying drawings, wherein a preferred embodiment is set forth for purposes of illustration.

In the drawings, wherein like reference numerals refer to like parts throughout:

Fig. l is a general assembly view of a thermostat, constructed in accordance with and embodying the principles of the invention, in accordance with one preferred embodiment thereof; in association with the adjacent mounting engine parts;

Fig. 2 is a vertical sectional view of the thermostat of Fig. l, on an enlarged scale, taken as indicated by the line 2-2 thereof;

Fig. 3 is a partial top view of the structure;

Fig. 4 is a transverse sectional view of the thermostat, on the line 4 4 of Fig. 3;

Fig. 5 is a detail perspective view of the strap support for the bellows; and

Fig. 6 is a detail perspective view of the control valve member, forming a part of the structure.

The present invention is particularly adapted for bypass thermostats of the type used for controllingthevow ICC of coolant liquid within internal combustion engines and the like, and is ,so illustrated in the drawings. It is to be understood, however, that the invention, and the various features thereof, may also be used for thermostatic com trol of fluids, in various devices and installations.

Referring more particularly to the drawings, in Fig. 1 a portion 10 of the block of an internal combustion engine is illustrated, said block defining an inlet passage for coolant fluid from which ,the fluid flows either to an outlet passage 12 leading to the engine radiator, or to a passage 14 in by-pass relation thereto, under thermostatic control.

The thermostat comprises a main casing or body member 16 having an outwardly extending lskirt or ilange portion 18, by means of which the thermostat is mounted in position within the engine block.

Secured to and depending from the casing or body 16 is a bellows support strap 2,0, the detailed shaping of which is best shown in Fig. 5. More particularly, the support strap comprises a base portion 22 arranged to receive and support the lowerend of the bellows 24, and to which the lower end of the bellows is hermetically sealed by solder or the like, as indicated at 26. Upstanding from the base or platform portion 22 of the strap is a pair of diverging arms 2 8, preferably ribbed for rength as indicated, the upper ends of these arms being provided with wing portions 30 lying against and curved to conform with the shaping of the vertical skirt portion of the casing 16. The upper parts .of the wings are staked firmly to the casing, as indicated at 32.

As best shown in Fig. 2, an auxiliary casing member or body portion 34 is carried ,by `and extends upwardly from the casing member 16, the parts being conveniently coupled by means of a press fit, supplemented if desired by soldering or the like, as indicated at 36. The upper end of the casing part 34 is beaded over, as shown at 3S, to thereby support a top plate member 40. This top plate member is provided with an annular valve seat `42, and with a central opening ,or passageway 44 communicating with the block passage 14.

The upper end of the bellows 24 is hermetically sealed to a valve stem 46, the upper end of which threadedly supports a valve member 48, the detailed shaping of which is best shown in Fig. 6. In assembling 4the bellows, valve stem, and valve, the bellows is first lled with the thermostatic fluid after which a ball 50 is driven into `the central opening of the valve stem to seal the same. The valve lis then threaded into the desired position of adjustment, after which the solder plug 52 is applied Lto lock the valve in adjusted position, and also further seal the bellows from leakage.

Referring to Fig. .6, it will be seen that the valve 48 is in effect a variegated poppet valve having an outer flange portion or skirt 54, and a more centrally disposed or inner skirt portion 56. The upper part of the skirt 56 cooperates with the valve seat 42, when the valve is in its upper dotted line position, as shown in Fig. 2;.whereas whenthe valve is in its lower full line position, the outer skirt portion 54 thereof cooperates with a conical section 58 of the auxiliary casing `part 34, which conical portion is provided with a plurality of passageways 60, Fig. l. As also best shown in Fig. .6, the lower part of the skirt 56 of the valve member is provided with an annular series of openings or passageways 62 so that fluid may pass upwardly through the body of the valve; andthe casing member 16 is provided with a pair of central openings 64, Figs. 2 and 4, in general alignment therewith. These latter openings are formed between the ribbed struts 66, Fig. 4, extending radially inwardly from the casing member 16, and provided at their inner portions withl a central sleeve 68 forming a guide bearing for-the valve stem.

When the valve is in Vits lower Yfull-line position, as

shown in Fig. 2, the outer skirt portion S4 thereof is seated upon and seals the openings 60; so that the uid or liquid passes upwardly through thethermostat, through the openings 64 and 62 and thence through the opening 44 of the upper plate member to the block passage 14. When the valve is in its raised position, as shown in dotted linesin Fig. 2, the opening 44 is sealed by the valve skirt 56, and the liquid passing upwardly through the casing openings 64 passes outwardly through the openings 60 to the block passage 12, the valve skirt 54 being at this time in raised position.

It will thus be seen that the variegated poppet valve 48 performs the dual functions of controlling uid llow both through the plate passageway 44, and through the casing openings 6i), in desired proportions as the valve is shifted between its operating positions. At the same time the valve member may be readily formed, by stamping operations or the like, and easily mounted in assembled position.

It will further be seen that the seats 42. and 58 for the valve member are both a part of the thermostat structure, so that the entire assembly may be pretested and fabricated at the factory without reference to, or close manufacturing tolerances being required in, the cooperative engine block. The several thermostat parts may all be readily formed, and easily assembled, providing a satisfactorily operable yet rugged and durable construction.

Attention is further directed to the manner of cooperation between the plate member 40, and the associated engine block parts. As shown in Figs. 1 and 2, it will be seen that the sealing of the plate 4l) to the associated block parts may be effected by a rubber gasket member 70, or the like, whereby to seal oif the block passages 12 and 14 from each other. However, the compressibility of this gasket member permits a relatively wide variation in manufacturing tolerances, while still providing an citeetive seal. Also, the capacity of the passageway 14 is determined not by the size of the block passage but by the size of the plate opening 44 which can be properly proportioned in relation to the capacity or size of the openings 60, so that proper proportioning of the fluid flow capacities is elected by the thermostat structure itself, again without reference to manufacturing tolerances within the associated engine block parts. The diameter of the block passage 14 may vary within relatively wide limits, but this does not change the capacity of the ow passage 44; and a single gasket member 70 of a given size may be employed notwithstanding such wide variation in the size of the associated block parts. This arrangement facilitates mounting and sealing of the thermostat in position. r

When the valve member 48 is in its lower position, as shown in Fig. 2, the iluid pressure in the approach side of the system acts upon the skirt 54, tending to hold the valve downwardly against the seat 58, and this force may be balanced against the pressures acting upon the upper face of the bellows, in a desired manner, to provide the proper pressure relations.

It is obvious that various changes may be made in the specific embodiment set forth without departing from the spirit of the invention. The invention is accordingly not to be limited to the specilic embodiment shown and described, but only as indicated in the following claims.

The invention is hereby claimed as follows;

1. A multitiow control thermostat for internal combustion engines and the like, comprising a sheet material casing including a cup-shaped portion mountable on an engine block and a tubular portion secured to an end of the cup-shaped portion, said end having an opening therethrough, plate means closing the free end of the tubular portion, said plate means having a central opening therethrough, said tubular portion having a lateral opening intermediate the ends thereof, a diaphragm shiftable in accordance with temperature, and a single valve member secured to the diaphragm and shiftable therewith, said Y valve member having an opening throughwhich tluid may 4 pass to said central opening, and a pair of valve portions respectively cooperable with said lateral and central openings.

2. A multitlow control thermostat for internal combustion engines and the like, comprising a casing, said casing having a centrally located inlet at one end, said casing having a central outlet opening at an opposite end and a plurality of annular outlet openings between said ends defining fluid passages in parallel, a diaphragm disposed exteriorly of said casing and shiftable in accordance with temperature, a valve stem connected to and shiftablc with said diaphragm, guide means for guiding said stem through said inlet and concentrically with said central openings, and a single valve member disposed substantially entirely within said casing and secured to the stem and shiftable therewith, said valve member having a central portion flaring away from the stern and generally toward said one end of the casing cooperable with the central outlet casing opening to effect the closing thereof when the valve is in one position, and an outwardly disposed annular portion flaring outwardly and generally toward said opposite end of the casing cooperable with said annular outlet casing openings to elect the closing thereof when the valve is in another valve position.

3. A multiow control thermostat Yfor internal combustion engines and the like, comprising a casing, said casing having a-substantially centrally located inlet at one end thereof, said casing having a central outlet opening at an opposite end and a plurality of outlet openings between said ends dening lluid passages in parallel, a diaphragm disposed exteriorly of said casing and shiftable in accordance with temperature, a valve stem connected to and shiftable with said diaphragm, guide means for guiding said stem through said inlet and concentrically with said central opening, and a single valve member secured to said stem and shiftable therewith, said valve member having a central portion cooperable with said central outlet opening to effect the closing thereof when the valve is in one position, and outwardly disposed annular portion cooperable with said other outlet openings to effect closing thereof when the valve is in another position, and said valve having an opening therethrough in series with the central outlet opening.

4. A multilow control thermostat for internal combustion engines and the like, comprising a casing, said casing having a pair of openings laterally offset from each other having valve seats and defining a pair of fluid passages in parallel, a diaphragm shiftable in accordance with temperature, and a single valve member secured to the diaphragm and shiftable therewith, said valve member having a generally conical inner portion cooperable with the valve seat of one of said casing openings to effect the closing thereof, a generally conical outer portion coopcrable with the Valve seat of the other of said casing openings to effect the closing thereof when the valve is in a different position, and said valve having an opening therethrough between said portions through which fluid passes in series with one of said casing openings.

5. A multiliow control thermostat as defined in claim 4, wherein said casing openings comprise a central opening in one end portion thereof, and a series of annular openings in an intermediate body portion thereof. f

6. A multiflow control thermostat for internal combustion engines and the like, comprising a casing having an inlet opening adjacent one end thereof, said casing having a wall section intermediate the length thereof and extending laterally outwardly from said one end, said wall section being perforated to provide an annular series of passages for fluid, a second wall section extending transversely of the casing and axially spaced from said iirst named wall section, said second wall section being provided with a substantially centrally disposed opening providing a fluid passage in parallel with the rst fluid passages, a diaphragm shiftable in accordance with temperature, a valve stenrconnected to said diaphragm and shiftable substantially coaxially of said central easing opening, and a valve member secured to said stem and disposed between said one casing and said second wall section, said valve member having an outer laterally extending flange portion cooperable with said annular passages to eiect the closing thereof when the valve is shifted in one direction, and a central portion cooperable with said central casing opening to eiect the closing thereof when the valve is shifted in the opposite direction.

7. A multiflow control thermostat as dened in claim 6, wherein said rst casing wall section is conically shaped, and wherein the outer flange portion of the valve member is conically shaped for cooperation therewith.

8. A multiow control thermostat for internal combustion engines and the like, comprising a casing, said casing having a laterally extending wall section intermediate the length thereof, said wall section being perforated to provide an annular series of passages for uid, a second wall section extending transversely of the casing and axially spaced from said first named wall section, said second wall section being provided with a substantially centrally disposed opening providing a uid passage in parallel with the first iiuid passages, a diaphragm shift` able in accordance with temperature, a valve stem connected to said diaphragm and shiftable substantially coaxially of said central casing opening, and a valve member secured to said stem, said valve member having an outer laterally extending ange portion cooperable with said annular passages to eiect the closing thereof when the valve is shifted in one direction, a central conical portion cooperable with said central casing opening to eifect the closing thereof when the valve is shifted in the opposite direction, and an annular series of openings through said valve member and between said central and outer llange portions defining uid passages through which uid flows to said central casing opening.

References Cited inthe file of this patent UNITED STATES PATENTS 1,328,855 Sweet Ian. 27, 1920 1,754,689 MacPherson Apr. 15, 1930 2,249,576 Payne July 15, 1941 2,457,991 Fernstrum Jan. 4, 1949 

